MITOSIS AND THE CELL CYCLE PowerPoint Notes

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1 1 Name: Date: MITOSIS AND THE CELL CYCLE PowerPoint Notes THE FUNCTIONS OF CELL DIVISION 1. Cell division is vital for all. This is the process that can create. 2. Cell Division always involves main processes: 1) The division of the contents. 2) The division of the contents. 3. There are FIVE main functions of cell division: 1) reproduction for cellular organisms. (like bacteria) as well as unicellular (like paramecium) reproduce asexually by a type of cell division called. Fig.1 Binary fission in bacteria. 2) reproduction for cellular organisms. Organisms like (an underwater animal) undergo cell division to produce (buds) from their bodies which eventually and become cloned offspring. This process is called. is when an organism performs a of one of its body parts. Some can autotomize their which will undergo cell division to into cloned offspring. Some plants reproduce without seeds or spores through asexual Fig.2 Autotomy of arms in some starfish.. One method of doing this is to undergo cell division to produce which are extensions from the parent plant that contain attached cloned offspring. Two types of plants that do this are. 3) reproduction in cellular organisms. In sexual reproduction, cell division is required for reasons: 1) to make like and. 2) to allow the multiple divisions needed to create a organism.

2 2 4) and of a cellular organism. To reach and attain, many organisms have to continue to perform cell division even after all essential body parts have formed. Fig.3 Male Human Growth and Development. 5) and of a cellular organism. Give three examples: 1) 2) 3) 4. Except during the creation of, cell division results in daughter cells that are genetically to and to the. To create identical daughter cells, this type of cell division must involve and a process called which involves the and of the DNA into two halves. Mitosis is a part of the. THE CELL CYCLE Fig.4 Cell Division. The Cell Cycle 5. Cell Cycle: 6. This involves main stages and can be represented in a pie chart: 1) 2) 3) The size of each pie slice roughly represents how much a cell stays in each part of the cell cycle, but there are great variations depending on the type of cell. Fig.5 The Cell Cycle

3 3 Interphase 7. Interphase: 8. Interphase can be broken down into stages: 1) G 1 Phase (Gap 1): The cell after cell division to reach full size (it may double in size). The cell performs its specialized depending on what type of cell it is. Fig.6 Various Cell Types This is the part of the cell cycle for most cells except for fast dividing cells and cells. Once organisms reach adulthood, some of their cells will again. These cells stop progressing through the cell cycle and go into where they will simply continue to perform their functions until they die. Give examples of three cell types that are like this: 2) S Phase (Synthesis): The DNA is creating copies of each chromosome. As well, the also to create pairs. Fig.7 S Phase Events 3) G 2 Phase (Gap 2): The cell for mitosis by undergoing rapid of its cytoplasm. The cell increases the synthesis of the needed to make the used in mitosis. The DNA is checked for replication that might have occurred during DNA replication in S Phase. This prevents (changes in the DNA code) from being passed to daughter cells.

4 4 Mitosis 9. Mitosis: 10. Mitosis is broken down into main stages and they can be represented by the acronym which stands for 11. However, the events that occur between and are important enough to create a fifth stage between these two called. Fig.8 Stages of Mitosis Cytokinesis 12. Cytokinesis: Animal Cells In animal cells, a forms to constrict the cell membrane in the middle of the cell and divide it. Plant Cells In plant cells, the makes cytokinesis more challenging. Instead of making a cleavage furrow, a plant cell makes a in the middle of the cell. The cell plate is made up of which contain the material needed to build the. The vesicles at the midline of the cell to create a new cell wall which completely the two daughter cells. Fig.9 Animal Cytokinesis Fig.10 Plant Cytokinesis

5 5 MITOSIS A CLOSER LOOK! G 1 Interphase 13. In this example, we will examine a cell containing (red, blue and green) in the initial parent cell. G 2 Interphase 14. After S Phase, each chromosome has undergone DNA replication. There are now. At this point, the DNA has yet so it is still and. This form of DNA is called. 15. The two identical sides of each duplicated chromosomes are called. The two sister chromatids are together at a region of the chromosome called the. 16. The centromere is where protein structures called assemble on either side of the sister chromatids. The kinetochores are the sites of for which the sister chromatids apart. 17. are protein filaments that serve various different functions within a cell. When they are used in mitosis or meiosis, they can be specifically referred to as. 18. The along with the that surround it form the which is the organelle responsible for the. Centrosomes are only found in cells. 19. Along with the DNA, the centrosome is in S Phase to produce the two centrosomes you see in G 2.

6 6 20. Fill in this chart to summarize the events in the various stages of mitosis. PROPHASE a) The centrosomes begin to to. b) begin to form between the two centrosomes. c) The begins to which the chromosomes to be sorted and divided in later stages of mitosis. d) The chromatin begins to and become, and. e) The begins to disappear. PROMETAPHASE a) The nuclear membrane is completely dissolved which allows the access to the duplicated chromosomes. b) The has disappeared. c) spindle fibers reach through the dissolving nuclear membrane and to the of each duplicated chromosome. These spindle fibers begin to the duplicated chromosomes along the midline of the cell called the (or metaphase). d) spindle fibers from opposite poles reach the midline and push against one another to the distance between the two centrosomes. e) spindle fibers help the centrosomes at opposite poles of the cell. f) All of the different types of spindle fibers help form a network of fibers called the (or ). METAPHASE a) The centrosomes are migrated to opposite poles. b) The spindle apparatus is formed. c) The nuclear membrane is dissolved. d) The spindle fibers have the duplicated chromosomes along the so that each sister chromatid of a duplicated chromosome faces poles. e) Correct at this stage helps to ensure that each new daughter cell will receive one sister chromatid from each duplicated chromosome when the sister chromatids are separated. f) At this stage, the chromosomes are, and at their most, hence the chromosomes are at their most easily observable state.

7 7 ANAPHASE a) The spindle fibers and the attached sister chromatids apart at the towards opposite poles. b) The spindle fibers push against each other to the cell and further separate the sister chromatids. c) Each chromatid becomes its own once separation has occurred. TELOPHASE a) This phase is essentially the of prophase. b) The spindle apparatus begins to. c) The chromosomes become and by and reverting back to their structure. d) A begins to reform around each set of chromosomes. e) The reappears in each nucleus. f) A (or in plant cells) begins to form which signals the beginning of which will separate the two new daughter cells. 21. Identify cells A-F as: interphase, prophase, prometaphase, metaphase, anaphase or telophase.

8 8 22. Identify cells A-E as interphase, prophase, metaphase, anaphase or telophase. (There s no prometaphase example in this image.)

9 9 Created by Anh-Thi Tang Tangstar Science Copyright February 2015 Anh-Thi Tang (a.k.a. Tangstar Science) All rights reserved by author. This document is for your personal classroom use only. This entire document, or any parts within, may not be electronically distributed or posted to any website including teacher or classroom blogs and websites.